Differences between Persian qanats and Roman aqueducts

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Differences between Persian qanats and Roman
aqueducts

• A short explanation and a comparisson
• by W.D. Schram MSc

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Overview

• Introduction on Roman aqueducts
• Introduction about Persian qanats
• Comparison
• An example

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Aqueducts definition

• An aqueduct is a channel or pipeline to transport
  water over a greater distance, from a water
  source to its destination often a city,
  sometimes a farm, factory or mill there the
  water is distributed.

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Aqueducts basic elements
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Aqueducts tunnels

• A masonry channel inside a tunnel (Cave de Curé,
  Gier aqueduct, Lyon, France)

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Aqueducts bridges

• One of the bridges in an aqueduct of Perge
  (Turkey), fully covered with calcareous deposits

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Aqueducts arcade

• Two aqueduct channels (70 and 88 km long, mainly
  subterranean) on top of a series of arches (Rome,
  Italy)

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Aqueducts the users

• Local fountain
• (Gerasa, Jordan)

• Baths (reconstruction)
• (Xanten, Germany)

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Roman aqueducts some 1500
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Qanats definition

• A qanat is a combination of
• - an infiltration gallery or mother well that
  collects water from an aquifer, and
• - an underground tunnel, connecting a series of
  vertical shafts, to transport water by gravity to
  the surface for direct consumption and / or
  irrigation.

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Qanats basic elements
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Qanats construction

• Muqanni

• Clay rings for reinforcements

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Qanats from the air

• Persepolis

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Qanats channel and shafts

• Qanat shaft (near Yazd)

• Shaft tops

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Qanats bridge

• One of the few qanat bridges. This one is from
  Kharanaq.

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Qanats distribution in Iran
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Qanats distribution worldwide
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Qanats in Europe ??

• A water supply system in Walferdange (Luxemburg)
  with a stepped channel and access shafts

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Qanats the users

• Place to scoop water

• Water distribution

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Side step water storage

• Water storage site

• Entrance

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Comparison 1 Physical Geography
Element Persian qanat Roman aqueduct
1a. Character of the terrain Alluvial fans in mountainous areas From mountainous to almost flat areas
1b. Climate Mainly in arid regions Semi-arid and wet areas
1c. Source Mother well(s) in an aquifer External spring, river, lake by exception a well or aquifer
1d. Type of source Delayed delivery Mainly instant delivery
1e. Place in the landscape 100 subterranean Some 20 above ground
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Comparison 2 Technology
Element Persian qanat Roman aqueduct
2a. Construction Subterranean channel with shafts Masonry channel or pipe, sometimes with manholes
2b. Builders Paid specialists / specialists Slave specialists, contractors, sometimes military personnel
2c. Course Almost straight line Sinuous, following the countour lines
2d. Works of art By exception (bridges, subterrenean dams and mills) Bridges, tunnels, arcades, siphons
2e. Distribution Sluice gates, timesharing systems Castellae divisoria
2f. Storage Only local, with modelst volumes No, behind some large bath houses
2g. Surplus water Reused in other qanats at lower level Flushing sewers and public toilets, fullers
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Comparison 3 Societal
Element Persian qanat Roman aqueduct
3a. Users Farmers and general public. By exception in private housing for cooling General public use and bath-houses. By exception industry, private individuals and farmers
3b. Ownership In cooperation (10 250 individuals). Sometimes rich individuals Public bodies, town councils
3c. Finance Members of the cooperation Locan maecenas, emporer, town council
3d. Status within society The only water source, essential for life, utilitarian Additional to existing sources, luxury, showcase of pride and power
3e. Present status Many still in use Almost all out of use, some reconstructed
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ExampleHadrians aqueduct in Athens
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Example

• The major factor applied to Hadrians aqueduct

Element As with qanats H aq Remarks
Source Aquifer(s)
Course Straight - See the map
Users General public and farmers /- General public and baths
Ownership Cooperation - City council
Status The only source of water - Additionally to existing wells and springs
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Conclusions

• Hadrians work had some elements in common with a
  typical qanat, but it was an aqueduct
• In general
• Although there are some similarities, qanats
  and aqueducts are quite different water supply
  systems
• Why is this important?
• There is enough misunderstanding of the word
  qanat.

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Problems ?!

• Tehran (2009 CE)

• Nonius Datus (150 CE) (Saldae, Algeria)